Self-lift carburetor



y 31, 1966 D. N. ARNDT ETAL 3,253,822

SELF-LIFT CARBURETOR Filed March 9, 1964 5 Sheets-Sheet 1 INVENTORJ-DOA/A10 4. 42/1/07- W/ZZ/AM C. 5ERZ/A/f AZV/IV A FfNTO/V May 31, 1966 D.N. ARNDT ETAL 3,253,322

SELF-LIFT CARBURETOR Filed March 9, 1964 5 Sheets-Sheet 2 gm, 1?ATTOE/WS'VS May 31, 1966 D. N. ARNDT ETAL 3,253,822

SELF-LIFT CARBURETOR Filed March 9, 1964 5 Sheets-Sheet 5 /63 E; E1 464e //V YEA/70 75 5 Sheets-Sheet 4 Filed March 9, 1964 ATTOR/VA'YS May31, 1966 D. N. ARNDT ETAL SELF-LIFT CARBURETOR 5 Sheets-Sheet 5 FiledMarch 9, 1964 United States Patent 3,253,822 SELF-LIFT CARBURETOR DonaldN. Arndt and William C. Eherline, Cass City,

This invention relates to a carburetor and more particularly to thattype of carburetor which is sometimes referred to as a self-liftcarburetor wherein fuel is pulled directly from the tank into thecarburetor without the use of a float system. A carburetor of the typeunder consideration is described in a patent issued August 1, 1961, toA. -P. Fenton No. 2,994,517.

It is an object of the present invention to improve on this type ofcarburetor by providing a novel control device which can be used with aconventional governor mechanism for use on-a lawn mower, chain saw, orother small device of this nature.

It is an object of the invention to provide a carburetor with a singlevalve control for both throttle and choke and further to provide acontrol which permits choke motion of the throttle at an appropriatetime in the starting cycle but which prevents the throttle from going tochoke position in an idling cycle or in a running cycle.

It is a further object to utilize a control spring for the governoraction which is mounted on the carburetor so that it can be calibratedby the carburetor manufacture.

It is another object to utilize this spring to remove objectional motionin the governor control mechanism.

A further object of the invention is the provision of a single controlelement which co-operates with a throttle mechanism to permit suitablechoke action when called for and to prevent such action whilecontrolling the position of the throttle valve during the running cyclesof the engine.

Another object of the invention is the provision of a carburetorconstruction utilizing a single control element in the mixing passageand providing for a venturi-controlled pumping action which is mergedwith a novel means of venting the tank to permit breathing whilepreventing the introduction of dirt and foreign objects.

A further object is the provision of a carburetor system of the typedescribed wherein a reservoir of fuel is retained above tank level inreadiness for a throttle opening motion.

Other objects and features of the invention relating to details ofconstruction and operation will be apparent in the following descriptionand claims.

Drawings accompany the disclosure and the various views thereof may bebriefly described as:

FIGURE 1, a top view of the assembled carburetor with control plate inOFF position.

FIGURE 2, an outside elevation of the assembled carburetor.

FIGURE 2A, a top view with control plate removed.

FIGURE 2B, a top with control plate in RUN position.

FIGURE 2C, a top view with control plate in CHOKE position.

FIGURE 3, a longitudinal section of a carburetor taken on line 3-3 ofFIGURE 2.

FIGURE 4, a transverse section of the carburetor taken on line 44 ofFIGURES 1 and 4.

FIGURE 5, a transverse section of the carburetor taken on line 55 ofFIGURES 1 and 2.

FIGURE 6, a transverse section of the carburetor taken on line 6-6 ofFIGURES l and 2.

FIGURE 7, a partial section taken on line 77 'of FIGURE 2.

FIGURE 8, a view of a cover plate for the fuel pumping system.

FIGURE 9, an enlarged view of the main housing with a diaphragm sheetapplied to the fuel pumping area.

FIGURE 10, an enlarged view of the main housing with a second diaphragmsheet applied to the fuel pumping area.

FIGURE 11, an enlarged view of the main housing fuel pumping area.

The control mechanism A carburetor body 20 has a connecting flange 22 tobe associated with the fuel intake of an engine, the body containing ashort passageway 24 (FIGURE 3) which connects to a long mixingpassageway 26 in which is mounted a control valve member 30 which, byreason of its bulky size, creates a restriction in the passageway. Theright-hand end of the passageway 26, as shown in FIGURE 3, is an airinlet passage 32 which will be suitably covered by an air filter in astandard way.

The control valve member 30, in the form of a thick block of metalshaped to turn in the passage 26, is notched to mount on a verticalshaft 34 which terminates in a rivet head 36 fastened to a smallactuator plate 40. The lower end of the shaft 34 is suitably mounted forrotation in a recess at the bottom of the passage 26. The control valvemember 30 is shown in FIGURE 3 in an OFF position. The position of thevalve 30 relative to the walls of the housing 26 can be controlled by anadjustment screw 42 which passes through a portion of the housing abovethe passage .26. The end of this screw co-operates to form a stop for asmall depending flange 44 on the. actuator plate 30.

Also on the top of the housing is a short circular projection 46 (FIGURE'6) which serves as a mount for a coil spring 48 having one hooked end50 (FIGURE 2A) surrounding a short stud 52 extending upwardly on plate40 and the other end 54 joined to a short tab 56 on a 'control plate 60which is pivoted on the top of the cylindrical extension 46 and held inplace by a screw 62. Also extending upwardly from the main housing 20 isa hollow riser 64 (FIGURE 2) which contains a small coil spring 66hearing at the top against a ball detent 68 which co-operates withdimpled recesses 70 and 72 in the lower surface of the control plate.

It will be seen that the tab 56, which holds captive the end 54 ofspring 48, is formed at the end of an arm 74 extending outwardly fromthe control plate 60, more or less parallel with a control arm 86extending radially from the pivot screw 62. A short tab 78 at one end ofan arcuate portion of the plate 60 serves as a positive stop for theclockwise rotation of plate 60, this tab seating against the wall of theriser 64. A second oppositely disposed tab 80 struck down from the bodyof the plate 60 serves as a limiting stop for the counterclockwiserotation of the plate 60 as viewed in FIGURE 1, this tab also seatingagainst the riser 64. Extending upwardly from the plate 60 adjacent oneedge is a vertical. arm 82 having a short horizontal tab 84 which willserve as a location for a Bowden wire if remote control is desired.

Additional radial tab 86, extending radially from the arcuate edge ofthe plate 60, serves to contact a grounding contact 88 to ground out theignition ofan internal combustion engine system when the control plateis moved to the extreme counterclockwise position. A small tab 90projects out from the plate 60 adjacent a notch 92 which, as will belater described, is designed to receive the pin 52 on the actuator plate40. A small hole 94 in the corner of actuator plate 40 serves as aconnection to a governor control of an internal combustion system in amanner which is standard practice.

With the parts as shown in FIGURE 1, the control valve block 30 isapproximately in the position shown in FIGURE 6. Any spacing of theproximate corners of the valve 30 relative to the walls of the passage26 will be controlled by the setting of the adjustment screw 42 bearingagainst the tab 44 on actuator plate 40. This is a neutral position alsofor the hooked arm 50 of spring 48, since in this position, it isexerting no pressure in either direction on the upright pin 52.

It will be seen that the screwing in of the pin 42 will move plate 40 sothat the control valve can be in a partially open position and thus inan idling position for an engine. At this point, the dimple 72 isengaged with the detent ball 68. The position of the plate 40, as shownin FIGURE 2A, is the same as shown in FIG- URE 1.

If the control plate 60 is rotated -in a clockwise direction to a RUNposition, shown in FIGURE 23, the dimple 70 will now be registering withthe detent ball 68 and the arm 50 of the spring 48 will have movedclockwise urging the pin 52 clockwise so that the pin is in contact witha cam surface 100 on the arcuate edge of the control plate 60. In thisposition, the control valve 30 will be substantially aligned with thedirection of the passage 26 so that the longitudinal edges of the valveare parallel with the side walls of the passage 26 as viewed in FIGURE6. In this posit-ion of the control plate 60, the valve 30 cannot movebeyond the position described because of the contact of the pin 52 withthe cam surface 100. This is true for any position between theoriginally described OFF position and the RUN position.

If the control arm 76 is moved to its full and extreme clockwiseposition as shown in FIGURE 2C, the pin 52 can then enter the notch 92.It is forced into the notch by the action of the spring arm 50 and inthis position the valve 30 of FIGURE 6 is rotated to the extremeclockwise posit-ion that it could occupy in the passage 26, this hearinga CHOKE position wherein outside air is cut off and the throttle openingis exposed to the full suction of the engine. In this position also, thesmall control tab 78 is against the riser 64.

It will thus be seen that with the control mechanism described for thevalve block 30, the valve can be in an idle position-OFF, a full openpositionRUN, or any intermediate position between these points. With thecontrol plate in this range, the pin 52 prevents motion of the valveblock to the CHOKE position by reason of contact with the cam surface100. Only when the control plate 60 is moved to its extreme position, asshown in FIGURE 2C, is the choke valve block permitted to move into thechoke position by reason of the action of the spring arm 50 and thepositioning of the notch 92. The tension of the spring arm 50, can becontrolled by the bending of the short arm 74 in one direction oranother to relieve and increase the tension on the arm 54 of the spring48.

The fuel system As shown in FIGURE 6, the mixing passage 26 is createdby reasons of the straight passage interrupted by the valve block 30which restricts the effective area of the passage causing a venturiaction. In the area of the valve block location is a main fuel inlet jet110 and just to the left of it is an idle jet opening 112. These bothopen into a longitudinal slot 114 in the side wall of the housing 20.This slot has an additional opening 116 leading to the air inlet side ofthe valve when it is in its full choke posit-ion to allow some air topass through the slot along with the gasoline that will be drawn intothe mixing passage. The housing 20 is intended to be mounted directly ona gasoline tank and the apertured flanges 118, 120 and 122 will serve tohold the body on to the tank. A flat side wall 138 on the body is shownin FIGURE 11 and the opening 124 is directly accessible to the interiorof the tank through the carburetor body. A draw pipe 126 extends downinto the tank below the fuel level and is mounted in the body 20generally being open to a small port 128 in the flat side surface 130 ofthe body 20. The slot 114, previously referred to, also opens to thissurface 130.

Similarly, a tortuous passage, starting at the opening 124, leads"upwardly through a port 132 and 134 to a horizontal run 136 whichterminates in a short vertical port 138 protected by a small hoodextension 140 forming a horizontal port 142 open to atmosphere. Passage124 is also connected through a port 144 to a small well recess 146which in turn is connected to a small passage 148 leading to a valverecess 150 in the surface 130.

Still viewing the device as shown in FIGURE 11, a relatively largecircular depressed recess is formed in the surface 130 and a hole 162leads from this recess directly into the passage 26. As the parts havebeen described in FIGURE 11, fuel is to flow through pipe 126 andpassage 128 into the valve recess 150 where it is moved up through theshort passage 148 to the well 146. Here it will either spill over intothe port 144 and back into the tank or it will be moved up to the slot114. The tank is vented to atmosphere through the hooded port 142 andthe respective passages 138, 136, 134, 132. All this is accomplished byreason of the application to the surface 130 of a combination diaphragmand seal sheet containing fiap valves and a flat cover plate 163 whichoverlies the surface 130.

This flat cover plate 163 is shown in FIGURE 8 wherein it will be seenit contains a circular depression or recess 164 which opens into a crosspassage 166 leading to a valve flap depression recess 168. This is alsointerrupted by an opening 170 which leads to the previously describedvalve flap recess 150 in the housing 28 when the parts are assembled inregistry. The recess 168 is also the location for a flap valve in thediaphragm controlling the passage 128 leading from the draw pipe 126.There is also a passage the flat cover plate 163 which originates in aslight depression 172 and passes through an interior passage 174 to arather small opening 176 in the face of plate 163. This passage connectsthe well 146 in FIGURE 11 to the slot 114 and the small hole 176 iscontrolled by a needle valve 178 mounted in a threaded extension 180 onthe outside of the cover plate. A spring 182 serves to prevent vibratoryrotation of the needle valve screw 178.

Between the cover plate 163 and the surface 130 is a combination seal:and diaphragm formed of two members shown in FIGURES 9 and 10. InFIGURE 9, a diaphragm sheet 184 is shown overlying the surface 130 ofthe housing and covering the recess 160. The two valve openings 186 and188 are exposed and the diaphragm also has openings 190 and 192 toconnect the Well 146 with the groove 114.

In FIGURE 10, a second overlay diaphragm member 194 has an opening 196adjacent the recess 160 but at the valve recesses there are flap valves1% and 200 while the same openings 190 and 192 appear as in thediaphragm sheet 184, When these two sheets are put together as shown inthe assembly in FIGURES 4 and 7, they form a seal between the coverplate and the housing. They also form a diaphragm wall for the chamher164 and flap valves for the two valve recesses 150 and 168. v

In operation, pulsations from the mixing passage 126 are exposed throughthe hole 162 and by recess 160 to the diaphragm area 202. This causesfluctuation intoand out of the chamber 164 sucking gasoline through thevalve flap 200 into the pass-age 170 in cap plate 163 where the secondvalve flap 198 is operating. Fuel is thus forced into the passage 148and over into the well 146. Excessive fuel spills over into the passage144 and back into the tank, but this well is constantly exposed to theopening 172 in the cover plate 163 which leads through the passage 174to the small controlled aperture 176 which, of course, leads to the slot114 opening to the main throttle valve jet 110 and the idle port jet112.

Thus, it will be seen that the fluctuations in the mixing passage 26will pump fuel from the tank into the well 146 where it becomesavailable to the jet openings 110 and 112 so that control valve 30 canin its respectively described positions control the flow of gasoline toan internal combustion engine. The plate 162 is suitably held on thebodies by screws 204.

It will be seen that with the above combination, the fuel tank of anassembly on which this carburetor is used can be sealed with a so-calledsealer cap since the tank is vented to atmosphere through the carburetoritself. With the cam control as described, the single control valvemember 30 cannot be shifted to choke position during a run or idleposition even though the governor is calling for more fuel in a lug downposition. The governor spring 48 controlling actuator 40, pivoted onprojection 46, is tied in with the control plate 60 avoiding backlashand it may be adjusted by slight bending of arm 74 to calibrate thespring for proper run position. Speed can be controlled by moving theplate 60 between the full run position and the off or idle position.Screw 42 is adjustable to control the idle position of actuator plate40.

If it is desired to increase the pulse pump diaphragm action, a slightrestriction at the air inlet side of the passage 26 may be accomplishedwith-a bafile insert.

- We claim:

1. A combination carburetor and control mechanism comprising:

(a) an air mixing passage of substantially constant cross-section,

(b) a single control valve member pivotally positioned in said passageto control the flow of air through said passage and dimensioned tocreate a reduced flow area in the passage in the vicinity of said valveto cause introduction of fuel into said passage through fuel ports opento the passage,

said valve being movable to an idle position in one extreme position, afull throttle position in a mid-position and a choke position in theother extreme position,

(c) means to pivotally mount said valve in said passage,

(d) an actuator member for said valve, said valve and actuator beingunrestrainedly movable between said extreme positions,

(e) a control member for said actuator to move said actuator member andsaid valve to various control positions in said passage, including idle,full throttle, or choke, and (f) means on said actuator member and meanson said control member operatively associated to 'mechanically blockmotion of said valve to choke position when said control member is inidle, full throttle, or intermediate positions.

2. A combination carburetor and control mechanism comprising:

(a) an air mixing passage of substantially constant cross-section,

(b) a single control valve member pivotally positioned in said passageto control the flow of air through said passageand having a thickness toreduce the flow area in said passage to create a venturi eifect in thearea of said valve to cause introduction of fuel into said passagethrough fuel ports open to said passage,

said valve being movable to an idle running posi tion in one extremeposition, a full throttle running position in a mid-position, and achoke position in the other extreme position,

6 (c) means to pivotally mount said valve in said passage, said valvebeing unrestrainedly movable between said extreme positions, and

(d) means to move and control the position of said valve in said passageto effect manual shifting of said-valve to running and choke positions,said means being operative to block motion of said valve to said chokeposition when said means is adjusted for a running position.

.3. A combination carburetor and control mechanism comprising:

(a) an air mixing passage of substantially constant cross-section,

(b) a single control valve member pivotally positioned in said passageto control the flow of air through said passage and having a thicknessto reduce the flow area in said passage to create a venturi effect inthe area of said valve to cause introduction of fuel into said passagethrough fuel ports open to said passage, 2

said valve being movable to an idle position in one extreme position, afull throttle position in a mid-position and a choke position in theother extreme position,

(0) means to pivotally mount said valve in said passage,

(d) an actuator member for said valve,

-said valve and said actuator member being freely movable to each of theextreme positions and intermediate points,

(e) a control member for said actuator comprising a manually operablemember adjacent said carburetor,

(f)'spring means connecting said manually operable member and saidactuator member wherein varying positions of said manually operablemember cause varying pressures on said actuator to shift it to operatingpositions in said passage, and

(g) means operably associated with said manually operable member toprevent motion of said valve to choke position when said manuallyoperable memher is moved to a predetermined position.

4. A combination carburetor and control mechanism comprising:

(a) an air mixingpassage of substantially constant cross-section,

(b) a single control valve member pivotally positioned in said passageto control the fiow of air through said passage and having a thicknessto reduce the flow area in said passage to create-a venturi eifect inthe areaof said valve to cause introduction of fuel into said passagethrough fuel ports open to said passage,

said valve being movable to an idle running position in one extremeposition, a full throttle running position in a mid-position, and to achoke position in the other extreme position,

(c) means to pivotally mount said valve in said passage,

(d) a first means movable to running and to choke positions foractuating said valve,

(e) a second means forming a control member for said valve,

(f) means associated with said first and second means wherein motion ofthe second means causes motion of the first means, and

(g) means to block the motion of said first means to a choke positionwhen said first and second means are in a predetermined relationship toeffect a running position of said valve.

5. A combination carburetor and control mechanism comprising:

(a) an air mixing passage of substantially constant cross-section,

(b) a single control valve member pivotally positioned in said passageto control the flow of air through said passage having a thickness toreduce the flow area in said passage to create a venturi efiect in thearea of said valve to cause introduction of fuel into said passagethrough fuel por-ts open to said passage,

said valve being movable to an idle running position in one extremeposition, a full throttle running position in a mid-position, and to achoke position in the other extreme position (c) means to pivotallymount said valve in said passage,

(d) an actuator member for said valve comprising a small plate pivotallymounted to move with said control valve member,

(e) a control member for said actuator comprising a plate pivotallyassociated with said carburetor in the vicinity of said actuator member,

(f) resilient means controllable in its position by said control memberand connected to said actuator member wherein said actuator member isurged to various positions by resilient means, and

(g) means interengaging said plates movable in response to movement ofsaid control member to block motion of said actuator member when saidcontrol member is in a predetermined position.

6. A combination carburetor and control mechanism comprising:

(a) an air mixing passage of substantially constant cross-section,

(b) a single control valve member pivotally positioned in said passageto control the flow of air through said passage and having a thicknessto reduce the How area in said passage to create a venturi effect in thearea of said valve to cause introduction of fuel into said passagethrough fuel ports open to said passage,

said valve being movable to an idle running position in one extremeposition, a full throttle running position in a mid-position, and to achoke position in the other extreme position,

(c) means to pivotally mount said valve in said passage, I

(d) an actuator member for said valve comprising a small plate pivotallymounted co-axially with said valve above a carburetor housing, a studupstanding on said actuator member spaced away from the pivot axisthereof,

(e) a control'member for said actuator comprising a plate pivotallyassociated with said carburetor housing in a plane parallel to theactuator member and on a pivot axis spaced from the axis of saidactuator member, said control member plate having an arcuate sectionalong one portion thereof terminating in an inwardly extending notchedportion positioned in the general area of said upstanding stud on saidactuator member,

(f) a coil spring having its respective ends projecting from said coil,said coil being pivotally mounted adjacent the pivot of said controlmember plate, one end being engaged with said stud and the other endbeing engaged with a portion of said control member plate, and

(g) said arcuate surface on said control member plate serving to contactsaid stud and block motion of said actuator plate to prevent movement ofsaid valve 8 to a choke position except when said control member plateis moved to the point that said stud member may enter said notchedportion.

7. A device as defined in claim 6 in which the portion of the controlmember plate associated with one end of said coil spring is adjustablerelative to said control member plate to increase or decrease thetension between the ends of said spring.

8. A device as defined in claim 6 in which adjustable screw means onsaid carburetor housing is positioned to contact a portion of saidactuator plate to limit its motion in the idle running position.

9. A combination carburetor and control mechanism comprising: i

(a) a carburetor body having an air mixing passage of substantiallyconstant cross-section with one end adapted to be connected to an engineintake and the other end serving as an air inlet,

(b) a single control valve member pivotally positioned in said mixingpassage to control the flow of air through said passage and having athickness to reduce the flow area in said passage to create a venturieffect in the area of said valve to cause introduction of fuel into saidpassage through fuel ports open to said passage, said valve beingmovable to an idle running position in one extreme position, a fullthrottle position in a mid-position, and to a choke position in theother extreme position,

(c) control means for controlling the position of said valve in saidpassage,

(d) a fuel supply system for said carburetor in said body including afuel tank inlet pipe, a well reservoir in said body,

(e) a pumping diaphragm connected with said manifold passage,

(f) pressure-actuated inlet and outlet valves responsive to pressure ofsaid pumping diaphragm to cause flow of fuel from said tank inlet tosaid reservoir,

(g) a first passage in said body connectable to a fuel 9 tank on whichsaid carburetor is mounted,

(h) an overflow passage connecting said reservoir to said first passageto permit excess fuel in said reservoir to return to tank, and

(i) a tortuous passage in said body connected to an air inlet adjacentthe top of said carburetor body at one end and connected to said firstpassage at the other end to admit air to a tank on which said carburetoris mounted.

10. A carburetor as defined in claim 9 in which an elongate recess insaidvbody paralleling said mixing passage is connected substantially atthe center portion thereof through a main port to said mixing passageand at the downstream end thereof in a smaller idle port to said mixingpassage and means adjustably to control flow of fuel from said reservoirto said elongate passage.

References Cited by the Examiner UNITED STATES PATENTS 2,873,731 2/1959Richardson 12399 2,982,275 5/1961 Doman 1231 19 2,994,517 8/1961 Fenton261-62 3,103,544 9/1963 Kalert 26l41 3,104,617 9/1963 Barr 1031503,141,048 7/1964 Schneider 261-41 KARL I. ALBRECHT, Primary Examiner.

1. A COMBINATION CARBURETOR AND CONTROL MECHANISM COMPRISING: (A) AN AIRMIXING PASSAGE OF SUBSTANTIALLY CONSTANT CROSS-SECTION, (B) A SINGLECONTROL VALVE MEMBER PIVOTALLY POSITIONED IN SAID PASSAGE TO CONTROL THEFLOW OF AIR THROUGH SAID PASSAGE AND DIMENSIONED TO CREATE A REDUCEDFLOW AREA IN THE PASSAGE IN THE VICINITY OF SAID VALVE TO CAUSEINTRODUCTION OF FUEL INTO SAID PASSAGE THROUGH FUEL PORTS OPEN TO THEPASSAGE, SAID VALVE BEING MOVABLE TO AN IDLE POSITION IN ONE EXTREMEPOSITION, A FULL THROTTLE POSITION IN A MID-POSITION AND A CHOKEPOSITION IN THE OTHER EXTREMET POSITION, (C) MEANS TO PIVOTALLY MOUNTEDSAID VALVE IN SAID PASSAGE, (D) AN ACTUATOR MEMBER FOR SAID VALVE, SAIDVALVE AND ACTUATOR BEING UNRESTRAINEDLY MOVABLE BETWEEN SAID EXTREMEPOSITIONS, (E) A CONTROL MEMBER FOR SAID ACTUATOR TO MOVE SAID ACTUATORMEMBER AND SAID VALVE TO VARIOUS CONTROL POSITIONS IN SAID PASSAGE,INCLUDING IDLE, FULL THROTTLE, OR CHOKE, AND (F) MEANS ON SAAID ACTUATORMEMBER AND MEANS ON SAID CONTROL MEMBER OPERATIVELY ASSOCIATED TOMECHANICALLY BLOCK MOTION OF SAID VALVE TO CHOKE POSITION WHEN SAIDCONTROL MEMBER IS IN IDLE, FULL THROTTLE, OR INTERMEDIATE POSITIONS.